public class E8 {

        public static void main(String[] args) {
            System.out.println("1 添加-------------------");
            add();
            System.out.println("2 删除-------------------");
            remove();
            System.out.println("3 修改-------------------");
            alter();
        }

        public static void add(){
            StringBuffer sb = new StringBuffer();
            sb.append("itcast");
            System.out.println(sb);
            sb.insert(2,"123");
            System.out.println(sb);
        }
        public static void remove() {
            StringBuffer sb = new StringBuffer("itcastcn");
            sb.delete(1,5);
            System.out.println("删除指定位置结果:" +sb);
            sb.delete(0, sb.length());
            System.out.println("清空缓冲结果：" + sb);
        }
        public static void alter() {
            StringBuffer sb = new StringBuffer("itcastcn");
            sb.setCharAt(1, 'p');
            System.out.println("修改指定位置字符结果:" + sb);
            sb.replace(1, 3, "qq");
            System.out.println("替换指定位置字符（串）结果:" + sb);
            System.out.println("字符串反转结果:" + sb);
        }


    }

